Insulating bushing



FIG. 1 is a perspective view from above of an insulating bushing embodying the present design;

FIG. 2 is a perspective view from beneath;

FIG. 3 is a front view thereof, the rear view being identical to the front view;

FIG. 4 is a right side view thereof, the left side view being identical to the right side view;

FIG. 5 is a plan view from above;

FIG. 6 is a view from beneath; and,

FIG. 7 is an environmental, perspective view thereof with the broken line showing of a fragmented surface and cables being for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an insulating bushing, as shown and described. 